<p>This rule raises an issue when a class decorated with <code>@Pipe</code> does not implement the <code>PipeTransform</code> interface.</p>
<h2>Why is this an issue?</h2>
<p>Angular Pipes are expected to implement the <code>PipeTransform</code> interface to ensure type safety and follow Angular conventions.</p>
<p>The <code>PipeTransform</code> interface defines the contract that all pipes must follow, requiring a <code>transform</code> method with proper
typing. Without this interface:</p>
<ul>
  <li> TypeScript cannot verify that your pipe implements the required <code>transform</code> method correctly </li>
  <li> The pipe may not work as expected if the method signature is wrong </li>
  <li> Code becomes less maintainable and harder to understand </li>
  <li> You miss out on IDE support like autocompletion and error detection </li>
</ul>
<p>Implementing <code>PipeTransform</code> makes your code more robust and follows Angular’s recommended patterns.</p>
<h3>What is the potential impact?</h3>
<p>Without implementing <code>PipeTransform</code>, pipes may have incorrect method signatures leading to runtime errors. The code also becomes less
maintainable and loses TypeScript’s type checking benefits.</p>
<h3>How to fix?</h3>
<p>Add <code>implements PipeTransform</code> to your pipe class and import the interface from <code>@angular/core</code>.</p>
<h4>Non-compliant code example</h4>
<pre data-diff-id="1" data-diff-type="noncompliant">
@Pipe({ name: 'test' })
class Test { // Noncompliant
  transform(value: string) {}
}
</pre>
<h4>Compliant code example</h4>
<pre data-diff-id="1" data-diff-type="compliant">
import { PipeTransform } from '@angular/core';

@Pipe({ name: 'test' })
class Test implements PipeTransform {
  transform(value: string) {}
}
</pre>
<h3>Documentation</h3>
<ul>
  <li> <a href="https://github.com/angular-eslint/angular-eslint">Angular ESLint</a> - Rule <a
  href="https://github.com/angular-eslint/angular-eslint/blob/main/packages/eslint-plugin/docs/rules/use-pipe-transform-interface.md">use-pipe-transform-interface</a> </li>
  <li> Angular Pipes Guide - <a href="https://angular.dev/guide/pipes">Official Angular documentation on creating and using pipes</a> </li>
  <li> PipeTransform Interface - <a href="https://angular.dev/api/core/PipeTransform">API reference for the PipeTransform interface</a> </li>
</ul>
